In the wake of the Aurora movie theater shooting, many people had the same questions: What kind of derangement is indicated by the horrific acts of James Holmes? What is wrong with his brain? How will his mental state play out in the courts?

What could explain Anders Breivik's shooting attack in Oslo, Norway? While this was being debated from the angles of politics, religion, and sociology, I wanted to ask this from the viewpoint of neurobiology.